Abstract: A spray nozzle designed to produce a spray or mist containing a high concentration of bubbles. Such a spray is particularly useful in mixing liquid fuel and air for burning within a combustion chamber, as for example in a gas turbine engine. The novel design includes a pair of swirl chambers generally axially aligned within the nozzle. Fuel or other liquid enters the first or forward swirl chamber in a generally tangential and laminar flow pattern, passes into the second or rearward chamber through an interconnecting orifice. Violent liquid and air mixing occurs in the second chamber and the mixture is then expelled as an aerated spray through the interconnecting orifice, the first chamber and a discharge orifice.

Abstract: In an orifice and nozzle for the passage of fluid which may contain solid particulates as contaminants, the orifice and nozzle includes an opening which is rectangular in a cross-sectional plane perpendicular to the axis of the fluid flow. The rectangular opening has a ratio of minimum width to minimum depth, or vice versa, of less than approximately 1.5, and preferably 1.0, and a ratio of the length of the opening to the lesser of minimum width and minimum depth of the opening of less than approximately 2.0, and preferably 1.0. The rectangular cross section together with these ratios prevents plugging by the solid contaminants.